4.3 Execute mode

For execute mode, the library path is automatically set, then a
program is executed.

The first of the mode-args is treated as a program name, with the
rest as arguments to that program.

The following components of mode-args are treated specially:

-dlopen file

Add the directory containing file to the library path.

This mode sets the library path environment variable according to any
-dlopen flags.

If any of the args are libtool executable wrappers, then they are
translated into the name of their corresponding uninstalled binary, and
any of their required library directories are added to the library path.